The principle. Developed by FBI hostage negotiator Mike Ackerman and popularized by Chris Voss, the Ackerman model is a structured four-move sequence for negotiating a price down (or up, if you're selling) that exploits the rhythm of concession-making.
The setup. You've decided your target price — the realistic, defensible number you actually want to land. Now you work backward through four planned moves.
The four moves (when you're the buyer pushing down — invert if you're selling).
- Move 1 — Open at 65% of your target. Anchors low. Sounds insulting only on paper; in practice, opens the negotiating range.
- Move 2 — If they push back, go to 85% of target. This is your second offer.
- Move 3 — Then 95% of target. A measurably smaller jump than the first two. Signals you're approaching your ceiling.
- Move 4 — Final offer at 100% of target. Use a precise, non-round number (e.g., $47,250 not $47,000) and add a non-cash sweetener ("…and I'll throw in the extended warranty / training package / Q1 onboarding for free").
Why the diminishing concessions matter. A 20% jump → a 10% jump → a 5% jump signals to the other side that you're nearing your absolute limit. A flat sequence (10% → 10% → 10%) signals there's more room and invites them to keep pushing.
Why the precise number matters. Round numbers feel arbitrary. "$47,000" sounds like an opening position. "$47,250" sounds like the output of a real calculation — and people instinctively believe it's closer to the truth.
Why the non-cash sweetener? It lets the other side leave with a win without you giving more cash. Cash concessions train the other side to keep grinding; non-cash concessions feel like generosity.
Inverted for sellers. If you're defending your price, the model still works — you just open high (135% of target), step down through 115%, 105%, then land at 100% with a precise number and a removed discount or a added freebie. Same psychology, opposite direction.
Where it fails. Cultures with very different bargaining norms (some Northern European B2B contexts) can find the opening move bizarre. Use judgment — but the structure (diminishing moves, precise final number, non-cash sweetener) is universal.